[6.12.y,49/60] drm/panic: avoid reimplementing Iterator::find

Commit Message

Miguel Ojeda March 7, 2025, 10:49 p.m. UTC

From: Thomas Böhler <[e-mail]>

commit c408dd81678bb0a957eae96962c913c242e069f7 upstream.

Rust's standard library's `std::iter::Iterator` trait provides a function
`find` that finds the first element that satisfies a predicate.
The function `Version::from_segments` is doing the same thing but is
implementing the same logic itself.

Clippy complains about this in the `manual_find` lint:

    error: manual implementation of `Iterator::find`
       --> drivers/gpu/drm/drm_panic_qr.rs:212:9
        |
    212 | /         for v in (1..=40).map(|k| Version(k)) {
    213 | |             if v.max_data() * 8 >= segments.iter().map(|s| s.total_size_bits(v)).sum() {
    214 | |                 return Some(v);
    215 | |             }
    216 | |         }
    217 | |         None
        | |____________^ help: replace with an iterator: `(1..=40).map(|k| Version(k)).find(|&v| v.max_data() * 8 >= segments.iter().map(|s| s.total_size_bits(v)).sum())`
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#manual_find
        = note: `-D clippy::manual-find` implied by `-D warnings`
        = help: to override `-D warnings` add `#[allow(clippy::manual_find)]`

Use `Iterator::find` instead to make the intention clearer.

At the same time, clean up the redundant closure that Clippy warns
about too:

    error: redundant closure
    --> drivers/gpu/drm/drm_panic_qr.rs:212:31
        |
    212 |         for v in (1..=40).map(|k| Version(k)) {
        |                               ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `Version`
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_closure
        = note: `-D clippy::redundant-closure` implied by `-D warnings`
        = help: to override `-D warnings` add `#[allow(clippy::redundant_closure)]`

Fixes: cb5164ac43d0 ("drm/panic: Add a QR code panic screen")
Reported-by: Miguel Ojeda <[e-mail]>
Link: https://github.com/Rust-for-Linux/linux/issues/1123
Signed-off-by: Thomas Böhler <[e-mail]>
Reviewed-by: Jocelyn Falempe <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
[ Reworded to mention the redundant closure cleanup too. - Miguel ]
Signed-off-by: Miguel Ojeda <[e-mail]>
---
 drivers/gpu/drm/drm_panic_qr.rs | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

Patch

diff --git a/drivers/gpu/drm/drm_panic_qr.rs b/drivers/gpu/drm/drm_panic_qr.rs
index 447740d79d3d..25edc69f8e22 100644
--- a/drivers/gpu/drm/drm_panic_qr.rs
+++ b/drivers/gpu/drm/drm_panic_qr.rs
@@ -209,12 +209,9 @@ 
 impl Version {
     /// Returns the smallest QR version than can hold these segments.
     fn from_segments(segments: &[&Segment<'_>]) -> Option<Version> {
-        for v in (1..=40).map(|k| Version(k)) {
-            if v.max_data() * 8 >= segments.iter().map(|s| s.total_size_bits(v)).sum() {
-                return Some(v);
-            }
-        }
-        None
+        (1..=40)
+            .map(Version)
+            .find(|&v| v.max_data() * 8 >= segments.iter().map(|s| s.total_size_bits(v)).sum())
     }
 
     fn width(&self) -> u8 {